Frequently a requirement for transceiver circuits that are coupled to a coaxial cable is to provide a constant impedance for the cable at all times to maintain the integrity of the communication system. This requirement becomes more exacting when a transceiver of this type is remotely deployed for long periods of unattended operation when the need for low power consumption becomes evident. Usually such transceivers are one of a number of like transceivers in an interrelated network which is designed to share the transceiver function with a host of other related electronic functions. A frequent design hurdle attendant such arrangement is that the various electronic functions might be provided in compact, integrated circuits or microminiaturized packages where the heat dissipation problems associated with undue, high power consumption can and do impose severe operational limitations.
One contemporary transceiver that operates in the standby mode sinks 110 milliamps from its positive power supply and about 88 milliamps from its negative power supply. High power requirements from the negative supplies frequently are drawn upon to assure the reliable actuation and responsive operation of the transceivers. These increased power consumption levels are largely attributed to the design complexity of the contemporary transceivers which is also reflected in a considerably increased cost per unit. While the above identified invention sets forth an improvement in the state of the art, even lower power consumption levels are desirable.
Thus, there is a continuing need in the state of the art for transceiver improvement that provides for a still lower power consumption which assures the presentation of substantially the same impedance to a coaxial cable not only during transmission but also during the standby and power off modes of receiver operation.